Make menu bar entries clickable by dragging from the header button and releasing on the entry

[a-khushal]

Closes #1912 (header bar and widgets sub-issue).

[Keavon]

!build

[github-actions]

📦 Build Complete for f5a6725
https://f16deb7d.graphite.pages.dev

[Keavon]

Your implementation removes the ability to click on the menus without them disappearing again immediately.

[a-khushal]

Can you please explain about the expected behaviour

[Keavon]

The expected behavior should be the same as with any other software application that has a menu bar, e.g. VS Code. Give that a try and experiment a bit.

[a-khushal]

@Keavon, can you please check now, I have pushed changes to the same branch.
I have implemented features similar to VS code's menubar:

• select a menu entry by dragging from the header and releasing on that entry
• right click on menu header to close the menu

[Keavon]

!build

[github-actions]

📦 Build Complete for 4f256e7
https://382330fa.graphite.pages.dev

[Keavon]

This breaks when holding down the mouse and moving left/right from one menu bar button to another, like from "File" to "Edit". It then requires several more clicks to regain a non-broken state so the menus work correct. Reference VS Code again for how you should be able to switch left and right between menus while click-and-release or click-and-hold ing.